dotnet/wpf · error · InvalidOperationException

InvalidOperationException(SR.OperationCannotBePerformed, e)

Error message

InvalidOperationException(SR.OperationCannotBePerformed, e)

What it means

CallDoDefaultAction wraps its non-critical exceptions and rethrows them as InvalidOperationException(SR.OperationCannotBePerformed, e). When the underlying Win32/MSAA default-action call fails with any non-critical error (COM failure, lost element, etc.), the proxy converts it into this generic operation-failed exception while preserving the inner exception.

Solutions

1. Inspect the InnerException to find the real root cause (COM hr, ElementNotAvailable, etc.)
2. Re-acquire the element and retry — stale references are the most common cause
3. Verify the control actually supports the default action via its accDoDefaultAction/defaultAction property
4. Catch InvalidOperationException around pattern calls and treat it as 'action not performed' in test logic

Example fix

// before
try { invokePattern.Invoke(); }
catch (InvalidOperationException) { /* cause lost */ }
// after
try
{
    invokePattern.Invoke();
}
catch (InvalidOperationException ex)
{
    Console.WriteLine($"Action failed: {ex.InnerException?.Message ?? ex.Message}");
    element = FindElementAgain(); // re-acquire stale reference
}

// Re-verify the element exists and is enabled before invoking:
if (element == null || !(bool)element.GetCurrentPropertyValue(AutomationElement.IsEnabledProperty)) return;

bool IsInvokable(AutomationElement e) => e?.GetCurrentPattern(InvokePattern.Pattern) is InvokePattern;

try { invokePattern.Invoke(); } catch (InvalidOperationException ex) { Log(ex.InnerException); ReacquireAndRetry(); }

When it happens

Trigger: Calling Invoke()/Toggle() on an MSAA proxy where the underlying DoDefaultAction (e.g. IAccessible::accDoDefaultAction or SendMessage) throws a non-critical exception — element vanished mid-call, COM error, or the action is not actually supported by the control.

Common situations: Target control disappears between the IsWindowEnabled check and the action call; MSAA provider returns a COM error for the default action; automating non-standard controls whose default action fails.

Understand the failure class

Background: UnsupportedOperationException and "is not supported" errors: when a library deliberately refuses a call — this error's family across 30 libraries.

Related errors

• ElementNotAvailableException
• ElementNotEnabledException
• SR.OperationCannotBePerformed
• Win32Exception
• Win32Exception(Marshal.GetLastWin32Error())

AI-assisted analysis of dotnet/wpf@81131a70a4 (2026-09-14). Data as JSON: /api/errors/ca165b62e0d10e2b. Report an issue: GitHub.

Appendix: source

Thrown at src/Microsoft.DotNet.Wpf/src/UIAutomation/UIAutomationClientSideProviders/MS/Internal/AutomationProxies/MSAANativeProvider.cs:1210

                throw new ElementNotEnabledException();
            }

            // If Toggle is ever supported for menu items then SetFocus may not be 
            // appropriate here as that may have the side-effect of closing the menu
            Misc.SetFocus(_hwnd);

            try
            {
                _acc.DoDefaultAction();
            }
            catch (Exception e)
            {
                if (Misc.IsCriticalException(e))
                {
                    throw;
                }

                throw new InvalidOperationException(SR.OperationCannotBePerformed, e);
            }
        }

        #endregion Private Methods


        //------------------------------------------------------
        //
        //  Private Fields
        //
        //------------------------------------------------------

        #region Private Fields

        //private delegate AutomationPattern PatternChecker(Accessible acc);

        // a struct holding an entry for the table below
        private struct RoleCtrlType

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